java.util.stream implementation will automatically convert a
stream into a
DAG when one of the terminal methods are called. The DAG
creation is done lazily, and only if a terminal method is called.
The following DAG will be compiled as follows:
IStreamMap<String, Integer> ints = jet.getMap("ints"); int result = ints.stream().map(Entry::getValue) .reduce(0, (l, r) -> l + r);